The UAB Center for the Study of Community Health, a University Wide Interdisciplinary Research Center, has adopted specific aims to (1) provide a University platform for community-based participatory research (CBPR); (2) engage stakeholders via education and service; and (3) pursue research that enhances community health. Long term objectives are to (1) develop CBPR tools and methodologies; and (2) create a unified community engagement portal for the University. The proposed 5-year prevention project advances these aims and addresses HIV/AIDS, a CDC Winnable Battle. HIV/AIDS prevalence is increasing disproportionately in the Deep South. The project focuses on HIV risk and protective behaviors and suboptimal HIV testing uptake identified in prior research. Goals are to: (1) reach at-risk African American emerging adults living in Birmingham-Hoover, AL neighborhoods experiencing the urban health penalty; and (2) offer population- sensitive and specific HIV prevention programs that are appealing, evidence-based, scalable, and sustainable using modern communication channels to engage individuals and contribute to changed social network norms. The project includes an evaluation of intervention efficacy, upon which an evaluation of intervention diffusion to peer networks is built. CITY Health II will evaluate an entertainment education (EE) intervention to promote HIV testing and protective behaviors and reduce risk behaviors using an integrated phone and web platform. A cluster randomized trial will recruit 700 participants using Respondent Driven Sampling to compare the efficacy of (1) established voluntary HIV counseling, testing, and referral (VCTR usual care control) to be offered at baseline and monthly for 3 months until testing is accepted; and (2) usual care plus 12 weeks of Entertainment Education (EE) serial drama episodes that deliver HIV risk reduction and health promotion messages using an Interactive Voice Response (IVR) system. Participants in the intervention condition will use Twitter to invite network members to listen to EE episodes on a study website. Thus, the study includes a controlled evaluation of EE for HIV prevention while also assessing a key dimension of peer-driven intervention effectiveness (uptake) under real world conditions. Follow-up includes 3 monthly IVR assessments and a 6- month interview. Hypotheses are: (1) Adding a social network intervention to VCTR will improve HIV testing uptake and protective behaviors and reduce risk-taking. (2) The network intervention will change individuals' HIV-related outcomes through changes in perceived norms and self-efficacy/outcome expectations. (3) Intervention condition participants with more media experience and larger networks will benefit more from the intervention, and intervention diffusion will depend on the same characteristics. CITY Health II will advance understanding of intervention efficacy and underlying mechanisms and will contribute to the next generation of HIV prevention approaches by combining an established individual-level intervention with a novel social network intervention. The intervention is peer-driven and accessible, with scalability potential.